Data Structure

Understanding Modern Tech: How GPS Works

For the longest time humanity has looked up at the stars and wondered. We have wondered what mysteries lay in the great beyond. And we have strived to reach out and finally move into the endless darkness above us.

We are lucky enough to live in an age where we can now venture into space. And, while it isn’t possible for just anyone to go into space, the general public has been benefitting from space-age technology for a while now. And today we are going to look at one of the most revolutionary and mind-boggling bits of tech at our fingertips. GPS.

What is GPS?

You will have heard of GPS no doubt. The letters of which stand for Global Positioning System. The idea is GPS can be used to pinpoint your position anywhere on the planet.

You will see GPS at work in a lot of modern devices. The first big public usage of GPS was in cars and Sat-Navs. You will most likely have made use of GPS to find your location and plot a route along the roads. Doing away with the old-school paper maps.

You will also find that nearly every modern smart-phone also makes use of GPS. If you’re like me and you lose your phone constantly you will keep making use of services like localiseruntelephone.frĀ or Findmyphone to locate your missing phone. These services make use of GPS to physically locate your missing phone. But how does it all actually work?

Space-Age Tech

So how does Space-Age tech come into all this? Simple. GPS technology works by making use of a series of satellites that are in constant orbit around the planet. There are roughly 30 of them currently up there for this purpose.

These satellites are used solely for the purpose of GPS. They are in constant communication with each other and a series of ground-bases placed at different locations globally. This all combines into one intricate web of connections that any GPS ready system can tap into.

How It Locates

So the big question is: How do these satellites locate anything. The answer is both simple and complex. The simple answer is that the satellites are constantly sending our signals. The earth is basking in these signals 24/7.

Let’s use our phone as an example. Our phone is a receiver in this instant. It listens for these signals. Upon hearing four of them, it can now work out where it is on the planet with startling accuracy.

But let’s look at the more complex answer. There is another element at play here and that is the ground-stations. These are massive satellite dishes positioned around the globe. Without them, the whole GPS wouldn’t work. The reason being is that these bases are used to tell us where the satellites are.

‘But we know where they are. They’re in orbit!’ You might be saying. And this is true, they are in orbit. But things in orbit don’t stay in one location. Let’s break it down.


Orbit works by manipulating gravitational forces. The further away from the surface of the planet you get, the weaker gravity is. But unless you have fully left the atmosphere you will still be pulled back to earth, however slowly it might be.

So things in orbit are still under the effects of the Earth’s gravity. But at an alarmingly small rate. They stay ‘afloat’ as it were by constantly moving in a circle around the globe Orbiting it. This means they are using the Earth’s gravity against it. By being spun around they stay above the planet. But as they move and the Earth moves, we need to be able to locate the satellites to know where we are. This is what the ground bases do.

So next time you lose your phone or bring up google maps, just remember you are currently working with a complex and powerful series of satellites hanging high above you, way out of sight. And take a moment to appreciate just how incredible modern technology really is.

Laura Hartley is a software development designer and a writer. Before joining, she used to work in the IT industry